Lord Janner must appear in court to face historic child sex abuse charges, a judge has ruled, despite the former Labour peer’s legal team saying he is “unfit” to stand trial due to dementia.

Chief magistrate Howard Riddle said the defense claim that Janner would suffer a “catastrophic reaction” to hearing the charges was not strong enough to excuse him from the proceedings.

The district judge added: “He wouldn’t have to enter pleas, he wouldn’t have to say anything. I imagine he would be here for less than two minutes. It matters not whether he understands the proceedings.”

Janner, 87, faces 22 charges of child sex offences which are alleged to have taken place in the 1960s, 1970s and 1980s.

He was initially declared unfit to stand trial, but the decision was reversed by a senior lawyer earlier in the year.

His lawyer Andrew Smith QC told the court hearing at Westminster Magistrates Court: “Lord Janner is not in attendance. The reason for that submission on his part is that he is unfit to face the court.”

But the chief magistrate Howard Riddle said the court must hear evidence from medical experts before a decision allowing him to miss the hearing could be made.

“This would appear on the face of it to be a section 51 hearing, he wouldn’t have to enter pleas, he wouldn’t have to say anything. I imagine he would be here for less than two minutes. It matters not whether he understands the proceedings,” he said.

“There is only one issue: is he fit enough to come through that door for less than one minute?” he added.

The decision to prosecute Janner was made by Director of Public Prosecution Alison Saunders in June. The U-turn prompted calls for her resignation.

Labour MP for Rochdale Simon Danczuk said Saunders had made a “catalogue of errors” throughout her handing of the case. The MP was a vocal campaigner in parliament for the prosecution of Janner.

The peer’s family, however, deny any claims Janner abused young boys at a local children’s home.

Janner’s case is also being examined by the independent inquiry into historic child sex abuse, and is expected to take evidence from the complainants.